Heart rate zones are all the rage among roadies, but are they just a bunch of unnecessary mumbo-jumbo for wannabe pros? Do the benefits of training in specific zones really outweigh the costs of investing in a heart rate monitor and spending hours pouring over data? Is it just a case of if you cant measure it, you cant manage it or is there actual science behind the obsession with heart rate zones? And what about the poor souls who train without them - are they doomed to be forever stuck in a plateau of mediocrity? Are heart rate zones just a crutch for those who cant handle the pain of old-school, gut-busting interval training? Can someone explain to me why heart rate zones are the be-all and end-all of roadie training, or am I just missing something?